marker interface for runtime type conversion. Classes of this type are used at runtime to convert an EJB argument or return type into another that can be understood for marshalling/unmarshalling. Implementing classes must have a single public static method named "convert" with one argument and returning a non-void type. example: public static class ListToString implements ITypeConverter { public static String[] convert(List strings) { return (String[])strings.toArray(new String[0]); } }